Spreadsheets and Modelling

A spreadsheet is a lot like a big calculator. You can use it to organise your finances and keep a track of what your incomings and outgoings are (so that you don't spend more money than you have), and you can use it to model what will happen if certain criteria are met (You can model the weather using a spreadsheet. Get data about previous years weather patterns and it can be used to predict what will happen).
You can display your findings in a table, or a chart to make it easy for other people to read and understand.

Remember! Rows go across and columns go up and down (Like the columns that hold up old Roman buildings!)
Each box in the spreadsheet is a cell.
A cell reference is the letter and number (co-ordinates) of your cell.

A formula is where you manually press all the commands one by one. When you are writing a formula you will use the following + - / *.
An example of a forumla is =A1+A2+A3
This website shows you the basics of formulas.

A function is where you use a command word and the computer can do most of the hard work for you. You highlight the cells you want to be included and the computer works out the answer.
An example of a basic function is =SUM(A1:B55)

Time saving tip! Drag the forumla down instead of typing it in each cell. The formula will automatically update for each box (although sometimes this isn't a good thing! See absolute cell reference).


Some common functions:
SUM - this adds up all of the cells in the range
MAX - the maximum value in the range is displayed
MIN - the minimum value in the range is disdplayed
AVERAGE - the average of the range is calculated
IF - if a criteria is met then the computer does one thing, if the criteria is not met then the computer does something else. This link gives you an example of an IF statement, and explains the different sections.

Goal Seek
This link explains what goal seek is, and this link shows you how to actually use it.

Conditional formatting
This is where cells are changed to a different colour depending on if a criteria is met or not. This link shows you where it is and gives you an example of how it could be used.

Absolute cell reference
This is where you always want to refer to the same cell in a formula or function. This is for when you want to drag a forumla or function down (rather than typing it in every cell) but you always want to refer back to the same cell as part of your formula.
To do this, when you first write your formula/function put a dollar sign before the letter and the number. So instead of having =A1 you will have =$A$1.
This link explains absolute cell reference with examples.

Graphs
Line graph: used to track changes over short and long periods of time. Best for when there are smaller changes (bigger changes look better with a bar graph). Line graphs can also be used to compare changes over the same period of time for more than one group.
Pie Chart: use when you are trying to compare parts of a whole, you should not use them to show changes over time.
Bar Graph: used to compare things between different groups or to track changes over time if the changes/differences are quite large.

This link shows the differences between the types and gives some examples.